Bertrand Arthur William Russell, 3rd Earl Russell (1872-1970), was a philosopher, historian, logician, mathematician, advocate for social reform, and pacifist. A prolific writer, he was a populariser of philosophy and a commentator on a large variety of topics. Continuing a family tradition in political affairs, he was a prominent anti-war activist, championing free trade between nations and anti-imperialism. He also authored Principia Mathematica (with Alfred North Whitehead), an attempt to ground Mathematics on the laws of Logic and the essay On Denoting. He was a vigorous proponent of nuclear disarmament, antagonist to communist totalitarianism and an outspoken critic of the Vietnam War. Previously he had been imprisoned and deprived of his Fellowship of Trinity College as a vigorous peace campaigner and opponent of conscription during WW1. He visited the emerging Soviet Union which subsequently met with his disapproval and vigorous campaign against Adolf Hitler in the 1930s. In 1950, he was awarded the Nobel Prize in Literature.